1. Field of the Invention
This invention relates to a press-contacting terminal for connecting conductors of a flat cable, used in an automotive wire harness or the like, to other conductors or an electronic/electrical equipment.
2. Description of the Related Art
As shown in FIGS. 6 and 7, a press-contacting terminal includes a plurality of press-contacting portions 3 each having a pair of press-contacting blades 1 and 1 opposed to each other with a slot 2 formed therebetween, and each of conductors 5 of a flat cable 4, together with a sheath 6 thereof, is grippingly inserted between the corresponding pair of press-contacting blades 1 and 1 (that is, inserted into the slot 2), and therefore is connected thereto.
More specifically, the slot 2 has a main portion 7 for being connected to the conductor 5 in a press-contacted manner, and an outwardly-spreading guide portion 8 for guiding the conductor 5 toward the main portion 5. Blade portions 9 and 9 are formed respectively at inner edges of distal end portions of the two press-contacting blades 1 and 1 exposed to the guide portion 8.
The blade portions 9 and 9 are formed by processing the inner edge portions of the distal end portions of the press-contacting blades into a tapering slanting surface-shape at the time when each press-contacting portion 3 is formed, for example, by blanking by the use of a pressing machine. The sheath 6 is cut by these blade portions 9 and 9, so that the conductor is exposed, and this exposed portion of the conductor is press-contacted with the press-contacting blades 1 and 1.
Here, in order to obtain the proper press-contacted condition, it is important that the center of each conductor 5 should be disposed accurately into line with the center of the corresponding press-contacting portion 3. Actually, however, the centers of the two are disposed out of line with each other within the range of their manufacturing tolerances.
In FIG. 6, A represents the pitch of the conductors 5, and B represents the pitch of the press-contacting portions 3. In this Figure, the relation, A greater than B, is established, and because of this pitch difference, the misalignment of the conductors 5 relative to the press-contacting portions 3 occurs (X represents the amount of this misalignment).
When this misalignment occurs, the conductor 5 engages one press-contacting blade 1, and is pressed in one direction, as shown in FIG. 7.
In this case, the conventional blade portions 9 and 9 are formed respectively at the inner edges of the press-contacting blades 1 and 1 of the press-contacting terminal as described above, and therefore the conductor 5 and the sheath 6 can move in the direction of the width of the cable only within the very narrow, flexibly-deformable range between the two blade portions 9 and 9, with the blade portions 9 and 9 biting into the sheath 6, and therefore the centering function of the guide portion 8 is much lowered.
As a result, the conductor 5 is deviated in one direction within the slot 2, or the conductor 5 is pressed hard against the blade portion 9 upon pushing of the conductor into the slot so that the conductor 5 is cut, which leads to a possibility that the connected condition is adversely affected. This phenomenon is conspicuous particularly when the press-contacting terminal is used at an intermediate portion of the flat cable where the degree of freedom of movement of the cable in the direction of the width of the cable is low, and it has been desired to improve this point.
It is therefore an object of this invention to provide a press-contacting terminal for a flat cable, in which the degree of freedom of movement of the flat cable in a direction of a width of the flat cable during a press-contacting operation is increased, thereby assisting in the centering of each conductor between a corresponding pair of press-contacting blades.
According to the present invention, there is provided a press-contacting terminal for a flat cable, comprising a press-contacting portion, wherein the press-contacting portion includes a pair of press-contacting blades opposed to each other with a slot formed therebetween, wherein a conductor of the flat cable is pushable into the slot so as to be connected to the pair of press-contacting blades in press-contacted relation thereto, and wherein the pair of press-contacting blades includes inner and outer blade portions for cutting a sheath during a press-contacting operation of the flat cable, the inner and outer blade portions are formed on inner and outer edges of each of the press-contacting blades respectively.
According to a second aspect of the present invention, the slot has a main portion for being connected to the conductor in a press-contacted manner, and an outwardly-spreading guide portion for guiding the conductor toward the main portion, the inner and outer blade portions are formed at the guide portion side distal end portion of each of the press-contacting blades.
According to a third aspect of the present invention, the distal end portion of each of the press-contacting blades is formed into triangular shape and has inner and outer slanting edges, the inner and outer blade portions are formed respectively on the inner and outer slanting edges.
According to a fourth aspect of the present invention, the following relation is established, Cxe2x89xa6D, where C represents the length of the inner blade portion, and D represents the length of the outer blade portion.
In the above construction, the blade portions are formed respectively at the inner and outer edges of each of the two press-contacting blades, and therefore when misalignment occurs, the cable can easily move in a direction to absorb the misalignment (The degree of freedom of movement in the direction of the width of the cable is increased), since the outer blade portion can cut the sheath in the outward direction.
Therefore, the centering function between the two press-contacting blades is enhanced, and the conductor, disposed out of line with the press-contacting portion, can be smoothly moved into a center portion of the slot, thereby securing the proper press-contacted condition in which the deviation of the conductor, as well as the cutting of wire elements of the conductor, is eliminated.
In the construction of the second to fourth aspect, the inner and outer blade portions are formed only at the distal end portion of the press-contacting blade, exposed to the guide portion, that is, only at the region where the centering of the conductor by the guide portion can be effected. Therefore, in contrast with the case where these blade portions are excessively long, there are not encountered disadvantages that the wire elements of the conductor are cut by the inner blade portion after the connection and that the sheath is excessively cut by the outer blade portion.
In the construction of the third aspect, the blade portions are formed respectively at the two (inner and outer) edges of the triangular distal end portion of the press-contacting blade, and therefore the tip (apex portion) of each press-contacting blade bites into the sheath to cut this sheath in a dividing manner, and therefore the blade portions can easily penetrate into the sheath. In the construction of the fourth aspect, the outer blade portion is longer than the inner blade portion, and a centering-assisting operation by the outer blade portion is positively assured during the time when the centering is effected by the inner blade portion. Therefore, by adding the third and fourth aspect, the centering operation is effected positively and smoothly.